#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main() {
	int n;
	cin >> n;
	vector<int> a;
	for (int i = 1; i <= 1000; i += 2)
		for (int j = 1; j <= i; j++)
			a.push_back(i);
	cout << a[n - 1];
	return 0;
}
